Train speeds

Question

The sum of the speed of 2 trains is 719.2 miles per hour. If the speed of the first train is 2.8 mph faster than the second train, find the speeds of both trains.

Answer 1

Hi Ryan,

 

Let's translate the English into math. . .

Let X = speed of the second train

 

the speed of the first train is 2.8 mph faster than the second train--> first train's speed = X + 2.8

 

The sum of the speeds is 719.2 mph--> X + X + 2.8 = 719.2

 

Combine the X's--> 2X + 2.8 = 719.2

 

Subtract 2.8 from both sides--> 2X = 716.4

 

Divide both sides by 2--> X = 358.2 mph = speed of the second train.

 

I'll let you figure out the speed of the first train.

 

Have fun.

 

Dan